MEXICO CITY — Mexico City’s assembly on Thursday passed legislation to legally recognize gay civil unions in the capital, the first such vote by a legislative body in the history of the conservative, predominantly Roman Catholic country.

Mexico City Mayor Alejandro Encinas has spoken in favor of the bill and was expected to sign it into law, while at least one conservative non-governmental group said it was considering seeking a court injunction against the measure.

The bill, which would not approve gay marriage, allows same-sex couples to register their union with civil authorities, granting them inheritance rights and other benefits typically given to spouses. Heterosexual couples who are not legally married can also be registered under the bill.

“This law ... does not require anyone else to change their thinking, nor does it hurt the concept of the nuclear family,” said legislator Juan Bustos of the left-leaning Democratic Revolution Party, or PRD, which has pushed for the law in the capital for years.

The bill has been severely criticized by the Catholic Church and conservative civil groups in the country, which is 90 percent Roman Catholic. The Mexican Council of Bishops has said the law is the first step toward legalizing gay marriage and adoption by gays, while the conservative National Parents Union has characterized it as “aberrant.”

Growing urban tolerance
While homosexuality is still taboo in many rural parts of Latin America, the region’s urban areas are becoming more tolerant. If the law is enacted, Mexico City will join the ranks of the Argentine capital, Buenos Aires, and the southern Brazilian state of Rio Grande do Sul, which already have approved civil unions.

At the national level, lawmakers in Costa Rica and Colombia have debated, but not passed, similar measures.

The Mexico City assembly passed the measure by a vote of 43-17, with all the opposition coming from the conservative National Action Party of President Vicente Fox and President-elect Felipe Calderon. The party is known for its opposition to abortion and support for traditional families.

PAN lawmaker Paula Adriana Soto said the law simply “conceals a marriage between people of the same sex,” which is prohibited by Mexico City civil law.

Mexico City, with a population of 8.7 million, is a federal district similar to Washington, D.C., with its own legislature. The PRD dominates the assembly, which is the first in Mexico to approve such a law.

Legislators in the northern Mexican state of Coahuila on the Texas border introduced a similar bill this week.

Dueling insults
As the debate over the bill took place Thursday, groups both in favor and against the measure rallied outside the legislative building, hurling insults at each other.

Jorge Serrano, of the National Pro-Life Committee, said his group would consider seeking a court injunction in the next few days to prevent the legislation from going into effect.

“This is really something sad for our country and it is a direct attempt against the family, because it constitutes the legalization of homosexuality and obviously it is going to lead to an increase in this social wrong,” Serrano told The Associated Press.

Tito Vasconcelos, one of Mexico City’s leading gay activists, said the law represents “Mexico’s entrance into the first world of democracy, along with other countries that recognize this type of union.”

Elsewhere on Thursday, a parliamentary committee approved proposals for same-sex marriages in South Africa, clearing the way for the passage of legislation there.

The Netherlands, Canada, Belgium and Spain have legalized same-sex marriage, while several other European countries have laws giving same-sex couples the right to form legally binding civil partnerships. In the U.S., only the state of Massachusetts allows gay marriage, while Vermont and Connecticut permit civil unions.